Evaluation of Fire Protection Systems in Cross-Country Natural Gas Pipeline Installations

Abstract

Cross-country natural gas pipeline systems constitute critical energy infrastructure transporting high-pressure flammable hydrocarbons across geographically diverse and often densely populated regions. Although modern pipeline networks demonstrate strong safety performance, incidents involving gas releases, ignition events, and station-level equipment failures continue to present significant fire and explosion risks. Fire Protection Systems (FPS) installed at compressor stations, intermediate pressure stations, sectionalizing valve stations, and customer gas stations are designed to mitigate such hazards. However, systematic performance-based evaluations of FPS effectiveness relative to statutory and international standards remain limited. This study presents a comprehensive technical evaluation of FPS in cross-country natural gas pipeline installations using a structured field assessment framework. The methodology integrates document review, inspection checklist development, HAZOP analysis, Quantitative Risk Assessment (QRA), fire load estimation, and consequence modeling. Performance benchmarking is conducted against applicable provisions of OISD, PNGRB Technical Standards and Safety Regulations (TSSR), NFPA fire codes, API fire protection guidance, and related statutory frameworks. Results indicate that while most installations satisfy minimum prescriptive compliance requirements, deficiencies are observed in system redundancy, integration of gas detection with emergency shutdown (ESD), reliability of fire water networks under single-failure scenarios, and periodic performance validation. Passive fire protection measures are often under-optimized relative to credible jet fire exposure scenarios. The study identifies critical design and operational gaps and proposes engineering improvements based on reliability modeling and risk-based prioritization. The findings underscore the necessity of transitioning from checklist-based compliance to performance-driven fire protection validation in pipeline infrastructure. The proposed evaluation model offers a replicable framework for regulators, operators, and safety engineers to enhance resilience and risk mitigation.

Introduction

The study evaluates the fire protection systems (FPS) of high-pressure natural gas transmission pipelines, which typically operate at 30–100 bar and consist of discrete high-risk nodes such as compressor stations, intermediate pressure stations, sectionalizing valve stations, and customer gas stations. Although pipeline rupture frequency is low, the consequences can be severe due to rapid gas release and formation of large flammable clouds, leading to hazards such as jet fires, vapor cloud explosions (VCE), flash fires, and secondary equipment fires.

While regulatory frameworks such as OISD, PNGRB (India), and NFPA/API (international) mandate fire protection provisions, most remain prescriptive rather than performance-based. Existing research largely focuses on failure probability and corrosion management, with limited evaluation of operational FPS reliability or integration with process safety systems like Emergency Shutdown (ESD). This study addresses that gap through structured field evaluation, reliability modeling, risk-based benchmarking, and engineering optimization.

The methodology included document review, field inspections, HAZOP, Quantitative Risk Assessment (QRA), performance benchmarking, and reliability analysis. Risk modeling assessed individual and societal risk, thermal radiation, explosion overpressure, and fire load density.

Key findings from technical evaluation include:

• Fire water systems often met compliance standards but lacked sufficient redundancy; single pump failures could reduce discharge below required design density.

• Gas detection systems frequently operated as alarm-only systems without automatic ESD integration, delaying mitigation.

• Clean agent systems (IG-541/NOVEC) showed maintenance gaps such as expired hydrotests and poor enclosure integrity.

• Passive fire protection in compressor areas was sometimes inadequate for credible jet fire durations.

• ESD systems exhibited single-point control failures and insufficient periodic valve testing, increasing escalation risk.

Gap analysis revealed that regulatory compliance does not guarantee performance under worst-case scenarios. Redundancy, maintenance quality, and integration between detection and isolation systems significantly affect reliability.

A case study of a 180 km transmission section identified issues such as inconsistent ring main pressure, detector calibration drift, delayed diesel pump startup, and incomplete fireproofing. After corrective actions—including added pump redundancy, ESD integration, passive protection upgrades, and real-time monitoring—QRA results showed a 35% reduction in individual risk and a 22% decrease in thermal escalation probability.

Conclusion

This study demonstrates that while cross-country pipeline FPS installations generally comply with prescriptive standards, performance-based assessment reveals systemic weaknesses in redundancy, integration, and reliability. Active systems without robust passive support increase vulnerability under credible worst-case fire scenarios.

References

[1] Drysdale, D. (2011). An Introduction to Fire Dynamics (3rd ed.). Wiley. Lees, F. P. (2016). Loss Prevention in the Process Industries (4th ed.). Butterworth-Heinemann. [2] Mannan, M. S. (2018). Lee’s Loss Prevention in the Process Industries. Elsevier. Oil Industry Safety Directorate. (2020). Standards for Cross-Country Natural Gas Pipelines. [3] Petroleum and Natural Gas Regulatory Board. (2019). Technical Standards and Safety Regulations. [4] National Fire Protection Association. (2023). NFPA Codes and Standards. American Petroleum Institute. (2018). Fire Protection and Safety Standards for Gas Facilities.

Copyright

Copyright © 2026 Devesh Dixit. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.